Old Content:

Quantum Cryptography: Not Quite So Useless

November 16, 2008 by Kyle Brady
Tags: Physics, Quantum Cryptography, Quantum Physics
As required by the FTC, a Full Disclosure is available - this piece adheres to the Code of Ethics

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Before we get started, let's do a quick review of physics:

1. "Regular physics" would be gravity, electricity, thermodynamics... all the fun stuff you see in real life that is useful on a basic human level.


2. "Quantum mechanics" is a branch of physics at the fundamental level, that has alot to do with the behavior of atoms and lots of tiny particles that may or may not exist.

Now that we got all of that out of the way, let's ride.

Quantum of Solace

The idea behind quantum cryptography is pretty simple, at least the imaginary sense.  Basically, a key is generated using the principles of quantum mechanics, and then is transmitted along with the communications (like a modern 128- or 264-bit key) using some fancy math to describe the key's properties and data.

But here's the kicker... because of the atomic nature of these keys, and the basic principles of quantum mechanics, these keys are naturally intrusion-aware.  By purely observing the "system" (the quantum keys), the properties of the system get changed, and VOILA! both parties involved know their communication safety has been breached.

Beam Me Up, Dr. Hilbert

This is pretty cool, right?  It can have huge implications for voice-based communications, email, and any other number of security-relevant issues... assuming we can figure out this whole quantum computing thing.

But a certain someone over at WIRED seems to think there are no practical / commercial applications.  Really, Bruce?  That's just as ridiculous as Dr. Caveman saying "Shoes!  Who needs them when we have sweet callouses?" back in the day.

State Vectors Are Cool

Charles Stross actually hit on this idea in his SciFi thriller Singularity Sky:  if you can pair devices with each other, on a quantum level, then you have encryption that is "unbreakable".

I mention this only because it's an allusion to my point.  Imagine people who are concerned with security, like the military.  Do you imagine that they would be interested in encryption that has such instantaneous breach notifications, as well as high levels of complexity?  I think so.

And if you can envision one-to-one phones that implement this technology, then take it a step further:  what about a "keychain" that stores and selectively uses your quantum keys?  Much like keeping an SSH key store, you'd be able to effectively authenticate other people, without needing a separately paired phone for each communication endpoint.

O(awesome) = greatness

The point is this:  just because a technology is so complex that it's not understandable to most people doesn't mean that it's useless.  Don't believe me?  Ask the average person how the Internet works...

I'm betting their answer will involve "a series of tubes" somehow.

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Quantum Cryptography in the News

• The BBC - "'Unbreakable' Encryption Unveiled"


• CNET - "Network security makes a quantum leap"


• The Register - "UK crypto boffins turbo-charge quantum cryptography"

Old Content posts are leftovers from a less structured, less civilzed era that are kept for posterity.
Kyle can be found on Twitter and MySpace, or reached via email.